Automatic tuner



Jur le 12, 1945.

LE ROY J. LEISHMAN AUTOMATIC TUNER Filed Jan. 7, 1944 Patented June 12, 1945 UNITED STATES .V 7

Le Roy J. Leishman, Los Angelea-Calif. j Application January 7, 1944,,Serlal 170-511 3201 3 Claims. (Cl;'74:-10 "f This application is a continuation in part of my application Serial No. 179,439, filed December 13, 1937, and issuing in part as Patent No. 2,339,177 on January 11,1944. 1

The invention herein disclosed relates 'to automatic tuners, and more particularly to those in which a plurality of independently-movable positioning levers turn a rotatable member to different predetermined positions. The objects of this invention are to provide means whereby the positioning levers of such tuners may be operated by push buttons having a plunger action; to afford a simple mechanism for transmitting motion at right angles from the positionable control shaft to a very close dial shaft; and to achievethese various objectives with apparatus that is simple and inexpensive. Still other objects'will appear as this specification proceeds.

In the accompanying drawing:

Fig. Us a section taken on line l-l of'Fig. 2, showing one lever of an automatic tuning mech anism and a push-button arrangement for con-- trolling its operation. 1

Fig. 2 is a front elevation of a push-button controlled mechanical tuner, showing the action'of the plungers and the connections to various other moving parts of the set.

Fig. 3 is a section takenon line 3-'-3 of Fig. 2, and shows a side elevation of the transmission'to the dial shaft.

Fig.4 is a side elevation, partly in section, of a vmodified mechanism in which the plunger operates horizontally.

'- Fig. 5 is a detail of Fig. 4. v

Fig. 6 is a side elevation, partly in section, of

a modification employing a rack and pinion.

Positioning lever Fl, Fig. 1, is pivoted on rod Q, which is journaled at one end in end-plate CI and. at the other end in end-plate C2, Fig.2,

lever Fl is shown resting on positionable member Al, Fig. 1, which may be of the type shown,

or any other'type adapted to lever control, such as the heart-shaped cams of Vass'elli, Patent No. 1,846,289, the internal cams of Bird,'Patent No. 1,925,651, the reciprocating racks and bars of Schaefer, Patent No. 1,906,106, or the positionable members of my own Patent No. 2,084,851. Positionable member A has a set screw Rand is is shown fastened to end-plate CI. by meansof rivets'orscrews in ears-Zlvand Z2, which are integral with thebar. Similar fastening means is used atthe opposite end of the bar, as indicated-in Fig. 2, where; ear Z5 shows in the drawing. Bar 'L is fastened inlike mannerto end-plate Cl bymeans'of lugs Z3 and Z4, Fig.

upward movement of the rod. 1 A spring J surrounds each plunger 'rod between thev bar L and thecollar- I, and presses the plunger upward until'the collar abuts-against'bar-E. Each p1un er rod passes through a slot or hole T in the top V of the radio cabinet, and through an aperture in escutch'eon D,- fastened to the cabinet byscrewsW. w 1

Buttons B may possess an index tab, not shown, or else escutcheon D may carry a long tab holder M positionedclose to the plungers and carrying an index tab O- fon'ea'ch plunger. Asindicated in Fig. 1', the tab holder has'a'window N for each -tab,"through which the-"tab may be seen. Gear Gl, Fig.2,is mounted .on shaft SI by means of'a set-screw orpinin hub Hl, which. abuts against end-plate Cl. Gear .Cl mesheswith gear G2 on shaft S2 of the tuning condenser or other resonance varying means. These gears A should have a ratio of"2'1 when using positionable members of the-type shown. Pulley XI .Iis mounted on shaft=S2 next to the hub H2 of gear X2 by means :of a pin or set-screw in its hub H3; .Thispulley cooperates with pulley-X2 on shaft" S3 adapted'to be turned by the regular tuning knob, notshown. Cord 8 is attached to pulley-Xi at point 9, and extendsaroundlthe opone of aplurality of such members mounted in 1 predetermined angular positionson shaft SI, and each is adapted to be engaged by one of a plurality of positioning levers, Flto F6, Fig'.- 2.

Plunger rods Pl to P5, Fig. 2; cooperate with.

l'evers' Fl to F6 respectively and pass through posite side of the pulley,through a hole in the chassis top Y,'-aroun'd pulley X2, through another hole in-the top of-thechassis, and thence around pulley'-XI,:to-which 'it is attached on the opposite side at a positionnot shown. Twopulleys X4 andXi, are-mounted on shaft S2 "between the-=condenser 2| and'collar I2 fixed on said shaft by a set-screw. Pulley X5: is fastend to shaftSZ bya set-screw in its hub H4. Acord H is attached to pulley X 5 at a point I5, from which point it- -extends downward and around thepulley and then up on the opposite side of this pulley and over*dial pulley X3 where 4 it'is attached atpoi'n-t |"6, Fig. 3. Another cord I1 is attached to pulley X3 'ata point on the op-' posite side to that shown in Fig. 3. "This cord guide holes i s E a d i s. 1 and 2- BarE passes ove'r'the pun-eyes indicated" in Fig. mm

then around pulley X4 to a connecting point 18. Pulley X4 carries a pin or hook l9, and is free to turn on shaft S2 betweenpulley X and collar I2, which carries a pin or hook I3. A spring J2, Fig. 3, is fastened to these two pins, turning pulley X4 in a clockwise direction and keeping the cord taut. Pulley X3 is adjustably fastened to dial shaft S4 by set-screw 20. Shaft S4 has a bearing in bracket 39 attached to the front of the chassis by screws 22. The opposite end of shaft S4 is journaled in bracket 23, Fig. 3, which may be attached to the chassis at any convenient location. Washers 24, between pulley X3 and these brackets, prevent undue friction.

clarity, and a pointer 26 is attached to the outer" Shaft S4 passes through the center of a calibrated-dial operation was performed. This will be true even with sloppy guides for the plunger, because a precision result does not in any way depend upon the accuracy of the plungers operation when a pivoted lever, rather than the plunger itself, is used to engage and rotate the positionable member.

Fig. 4 illustrates a modification of the mechanism just described, but also embodies the principle of an intermediate positioning lever to transmit motion from the plunger to a rotatable positionable member. In this form, the positioning lever F has a projection 23 at the pivoted end,

7 and this projection has a lug 29 extending transend of this shaft. It will be noted that there is little clearance between pulley X3 and pulleys X4 and X5. This lack of freespace makes'it impossible to insert aspring in one of the cords,:and the small sizeof thepulleys makes it impossible to run the cord through a hole in the periphery of the pulley and fasten, it to the interior by means of a spring, and therefore neither of these methods may be used for keeping the cords taut; but the construction shown here removes all play in the transmission between the two shafts at right angles and may be used wherever there is any clearance at. all between the necessary pulleys or reels;

A tuner of this type may be adjusted in the following described manner so that the depressing ofany button-will bring in a predetermined station. The button on one of the ,plungers, say PI, is pressed down, causingcthe :button, collar and lower end to assume thepositions indicated in dotted lines, Fig. 1. During this movement,the plungerengages lever Fl, resting on positionable member Al, moving these twoparts to the positions shown in dotted lines. If member Al should be found at an angle 180 degrees from that shown in the drawing, it will be obvious that lever Fl will rest .on the curved end Kl of member AI, and

that the downward movement of the plunger and lever will in that casealso move (the positionable .member to the position shown indotted lines.

This will also be true-of any 'intermedia'teposition. While, the button is held down, set-screw R .is loosened by means of a screw driver inserted through hole U in plate 21., which connects endplates CI and C2 and cooperates with bars E and L to hold the frame rigid Theloosening of this set-screw permitsshaft S1 to turn freely while member A! is held stationary. The desired starangement previously explained. After the de- I sired station has been carefully tuned in, set-screw R is again tightened. Otherpositionable memversely from the projection, as will be more clear from Fig. 5. This lug is engaged by the end of plunger P, Fig. 4, and the operation of the plunger turns lever F on pivot Q until the various moving parts occupy the positions shown in dotted lines. Lever F in turn rotates the control shaft as explained in the description of previous figures. The escutcheon D is shaped so that it extends into the opening T inthe panel V. This feature makes it unnecessary for button B to extend so far from the panel in its rest position, the full stroke nevertheless being permitted by the fact that the button movesinto, or even beyond, the plane of the panel. This construction is very satisfactory on heavy receiving sets, but when used on light table models the pressure required on button 13 is suificient to move the set unless it is held in place.

It will be obvious that the mechanism of :Fig. 1 could be oriented degrees to enable the plunger to move in a horizontal plane, but this would makeiit necessary to adjust the positionable members from the top of the set rather than from the back. The modification illustrated in Fig. A leaves the levers and rotatable members in the positions shown in Fig. 1, thus permitting the adjustments to be made from the back of the set, but, the introduction of projection 28 and lug 29 make it possible to use a button that pushes in, rather than down.

The mechanism depicted in Fig. 6 is another modification that permits the buttons to be pushed from the front, rather than the top, of the set, and the adjustments to be made from itheback. Pinion G3 is attached to the back of lever F. Rack 30 meshes with the pinion and is rigidlyattached to plunger P by screws 3|. As this plunger rod has no spring, it is moved to its outward inoperative position by the action of spring J attached to lever F. The pressing of button B moves the rack and rotates the pinion and lever around pivot Q. The movement of lever F is utilized to operate the tuner. Other features of the operation and construction of this modification will be clear from the reference characters, as they all refer to components having the same functions as those bearing the same reference numbers or letters in previously described figures.

Various other modifications, additions, omissions and substitutions may also be made without departing from the spirit of the invention, typical embodiments of which have been described. I

My. claims are: a

1. In a radio device, a combination including: a first shaft: asecond shaft at right angles to said first shaft; a first pulleyon said first shaft; a 'second pulley keyed to said second shaft; a third pulley on said second shaft; a flexible member-connecting said first andsecond pulleys; a flexible 'memberconnecting said first and third pulleys;

and a spring attached betweensaid third pulley and a point rigid with said second shaft said'third pulley adapted to tighten said flexible members under action of said spring.

2. In a radio device, a combination including: a rotatable element; a shaft disposed at an angle to the rotational axis of said element; a sleeve on said shaft; a part rigid and concentric with said shaft and having substantially the same diameter as said sleeve; flexible means connecting said ele-v a rotatable element; a shaft; a sleeve on said shaft; a part rigid and concentric with said shaft and constructed and arranged to act substantially as a pulley; a first flexible member connected to and passing at least partially around said element and connected to and passing at least partially around said part; a second flexible member connected to and passing at least partially; around said element in an opposite direction to said first memberand connected to and passing at least partially around said sleeve in a direction opposite to that in which said first member passes around said part; said sleeve angularly movable on said shaft for purposes of tightening said flexible members to remove play between said element I and said shaft; and means for holding said sleeve on said shaft in an angular position in which said members are taut. Y

LE ROY J. LEISHMAN. 

